1. Field of the Invention
The present invention relates to a three-dimensional (3D) image display device and an electrochromic module of the 3D image display device, and more particularly to a 3D image display device and its electrochromic module for changing a direction of displaying 3D images.
2. Description of the Related Art
At present, there are two types of 3D images, respectively: a 3D image viewed by naked eyes and a 3D image viewed by wearing a pair of shutter glasses.
With reference to FIGS. 1 and 2 for schematic views of a conventional 3D image display device for generating a 3D image by a pair of shutter glasses and its synchronous control process respectively, after a light emitted from a backlight 13 passed through an LCD panel 12, both left and right eyes will receive left-eye image data and right-eye image data of the 3D image display device 1 at different time points to produce a visual separation effect. The left-eye image data and right-eye image data displayed alternately must be operated by a shutter glasses 11 and a control circuit (not shown in the figure) synchronously, wherein a switch signal is provided for controlling the ON/OFF of the left and right eyes of the shutter glasses 11. After the left and right eyes are turned ON/OFF, and the switch timing is synchronous with the images received by the LCD panel 12, and the left-eye image data are displayed, the shutter will screen the vision of the right eye. On the other hand, when the right-eye image data are displayed, the shutter glasses will screen the vision of the left eye. As a result, the left-eye and right-eye images can be displayed alternately and quickly. With the persistence of vision, a 3D visual effect is achieved, and such 3D imaging method is called “time division”.
In addition to the time division, there is a wavelength division, wherein a relatively red and green screen is processed for the left-eye and right-eye images first, and a viewer wears a pair of color glasses with red color for the left eye and green color for the right eye, such that the viewer's left eye can see the red left-eye image only, and the viewer's right eye can see the green right-eye image only, and the left and right screens of different colors are processed to create 3D images.
In addition to the device of the foregoing two types of divisions, there is a 3D image display device manufactured by using the Pulfrich effect. The 3D image display device comprises a pair of Pulfrich 3D glasses, wherein one of the lenses of the 3D glasses further comprises a neutral filter, and both pieces of the left-eye lens and right-eye lens have different light transmittances, and our brain responds to a darkness stimulation slightly slower than a brightness stimulation, so as to produce an optical illusion. Although both of our eyes can see the same image, when the image is passed through a light filter, the speed for an eye to transmit the image to our brain is slower that that of the other eye, such that a virtual spatial depth can be created to produce the 3D effect.
In the method of displaying 3D images through a pair of 3D glasses, related technologies are mature and used extensively in movie, television and projector industries. However, a pair of glasses is required, and thus it creates a problem to users who already wear a pair of near-sighted or far-sighted glasses. In addition, there is a hygiene issue when the 3D glasses are used in public, and many users feel uncomfortable and have the side effects of dizziness and nausea. Wearing a pair of 3D glasses may be a psychological burden to some users, and an obstacle to the development of the 3D image technology.
In bare eyesight 3D display technologies, there are two main types of structures, respectively: a lenticular lens and a barrier, wherein the lenticular lens arranges a plurality of slender convex lenses continuously along the direction of an axis to produce different viewing figures of left and right eyes by the principle of optical refraction. Compared with the barrier type, the lenticular lens has a smaller loss of light and a better brightness, but there is a limited refraction effect at edges of the lens since the lenticular lens achieves the effect of splitting a light by refractions, and thus the refraction is not as good, or it is difficult to control the precision during the manufacture of the lenticular lens, so that a stray light may be produced easily during its application, and the overall display effect is affected adversely.
In addition, the barrier type uses a whole row of barriers for restricting lights from projecting from certain angles, and only allowing viewing images at certain angles to be transmitted to the viewer's left and right eyes to produce a 3D image. Compared with the lenticular lens, the barrier type provides a sharper image for a single eye, but its structural characteristic will lower the overall image brightness and resolution.
As the material technology advances, electrically conducted electrochromic materials with the coloration and decoloration properties are gradually used as a parallax barrier for producing 3D images. As disclosed in R.O.C.(TW) Pat. No. M368088 entitled “Integrated electrochromic 2D/3D display device, R.O.C. Pat. No. M371902 entitled “Display device for switching 2D image/3D image display screen”, R.O.C. Pat. No. I296723 entitled “Color filter used for 3D image LCD panel manufacturing method thereof”, the electrochromic material is used as a parallax barrier structure for displaying 3D images, but both patents of M368088 and M371902 have a common drawback of lacking a necessary electrolyte layer required by electrochromic devices, since ions are not supplied to the electrolyte layer of the electrochromic layer, and the electrochromic device cannot produce the reversible oxidation or reduction to complete the change of coloration or decoloration, so that the aforementioned patents are not feasible in practical applications. In addition, the transparent electrode layer and electrochromic material layer of the parallax barrier device are grid patterned, and whose manufacturing process requires a precise alignment for coating, spluttering or etching each laminated layer, and thus the manufacturing process is very complicated, and the resistance will be increased to slow down the response time, and all laminated layers are grid patterned, so that a hollow area is formed between grids, and the overall penetration, refraction and reflection of the light will be affected. Even for the general 2D display, the video display quality of the display device will be affected to cause problems related to color difference and uneven brightness.
In addition, the prior art for displaying 3D images displays the 3D images in one direction only. As to the portable or mobile electronic products such as mobile phones, personal digital assistants, navigators, users can only turn the electronic products to a specific direction to view the 3D images, but the users cannot change the angle for a 3D display, and such application is very inconvenient.